A multi-parameter monitoring system for NPT5 type air compressor of railway diesel locomotive

Abstract

The utility model belongs to the technical field of equipment monitoring, provide a diesel locomotive NPT5 type air compressor multi -parameter monitoring system, solve the defect that the existing NPT5 type air compressor only relies on total air pressure relay control, has no key parameter monitoring. The system includes control box module, exhaust temperature detection module, axle temperature detection module, oil temperature detection module, oil pressure detection module, exhaust temperature detection module, axle temperature detection module, oil temperature detection module, oil pressure detection module is connected with control box module respectively, and oil pressure detection module real -time monitoring air compressor main oil way lubricating oil pressure, oil temperature detection module detects lubricating oil temperature, axle temperature detection module monitors the axle temperature of main bearing, exhaust temperature detection module monitors exhaust temperature, this system can remind the attendant when air compressor technical parameter is unusual, if the attendant does not handle, then control air compressor automatic stop, thereby avoid equipment failure to expand, reduce equipment failure loss, reduce the repair expense, ensure locomotive operation safety.

Description

Technical Field

[0001] This utility model belongs to the field of equipment monitoring technology and relates to the monitoring of air compressors in railway diesel locomotives, specifically a multi-parameter monitoring system for NPT5 type air compressors in diesel locomotives. Background Technology

[0002] Railway diesel locomotives are equipped with air compressors, or simply air compressors. The air compressor is the main air source equipment for diesel locomotives, providing compressed air for the locomotive's braking system and other control functions. The proper functioning of the air compressor directly affects the safe operation of the locomotive and rolling stock. The air compressor has a rated speed of 1000 rpm. Its main moving parts, such as the crankshaft front and rear bearings, crankshaft journals and connecting rod bushings, and piston pins and connecting rod small end bushings, all utilize forced pressure lubrication. Its stable operation relies entirely on its efficient pressure lubrication system. However, many factors can cause air compressor failures, such as: low oil level in the oil sump; blockage in the oil lines; leakage in the main oil passage and safety valve; main oil pump failure; improper bearing clearance; crankshaft and connecting rod failures causing excessively high oil temperature; and failures in the air valve and intercooler causing excessively high exhaust temperature. Currently, there are no monitoring and protection devices for the NPT5 type air compressor during startup and operation. This leads to the failure of the air compressor not being detected in time, allowing continued use to exacerbate the problem or even render the air compressor unusable, resulting in the locomotive being taken out of service.

[0003] Secondly, the air compressor operates frequently during locomotive operation and is located at the front of the locomotive, far from the driver's cab. When the locomotive is running and the air compressor is working, the crew cannot easily leave the driver's cab to observe the air compressor's operating status and confirm its proper functioning. Furthermore, due to the distance from the driver's cab, abnormal noises emitted by the air compressor during operation are often difficult to detect due to interference from the diesel engine or other mechanical noises. There have been numerous instances where leaks or low lubrication pressure in the air compressor's lubrication system have caused severe damage to the crankcase mechanical parts; high exhaust temperatures caused by intercooler or air valve malfunctions have gone undetected, ultimately leading to burnt-out crankshafts, bearings, connecting rods, main bearings, cylinder scoring, burnt air valves, and even complete air compressor failure.

[0004] The NPT5 air compressor is started and operated by a DC motor. The electrical control system is automatically controlled by the air compressor control switch, the main air pressure relay, and the DC contactor. Its electrical control does not have relevant monitoring and protection devices for the air compressor lubrication system and mechanical devices in case of failure.

[0005] After the locomotive starts normally and generates electricity, the air compressor unit will begin operation. Pressing the air compressor control switch will activate the main air reservoir pressure relay if it is below 750 kPa. This relay will connect the coil control circuit of the air compressor motor contactor, causing the contactor to operate and connect the main contacts to the air compressor motor power supply. The motor will then drive the air compressor to start normal operation. When the main air reservoir pressure reaches 900 kPa, the main air reservoir pressure relay contacts will open, de-energizing the motor contactor coil and causing the main contacts to open, stopping the air compressor. When the locomotive is operating as a standalone unit, the air compressor operates for 54 seconds from when the main air reservoir pressure drops below 750 kPa until it reaches 900 kPa. If the air compressor's mechanical or lubrication system malfunctions, the existing electrical control system will not recognize the problem. If the main air reservoir pressure drops below 750 kPa, the system will control the air compressor motor to start, driving the air compressor to operate. Utility Model Content

[0006] The purpose of this utility model is to provide a multi-parameter monitoring system for the NPT5 type air compressor of a railway diesel locomotive. This system monitors the technical parameters of the air compressor after startup and during operation. When the technical parameters of the air compressor are abnormal, it alerts the crew. If the crew does not take any action, the system can automatically shut down the air compressor, thereby preventing the equipment failure from escalating, reducing equipment failure losses, reducing maintenance costs, and ensuring the safe operation of the locomotive.

[0007] The technical solution adopted by this utility model to achieve the above objectives is as follows: A multi-parameter monitoring system for an NPT5 type air compressor in a railway diesel locomotive includes a control box module, an exhaust temperature detection module, an axle temperature detection module, an oil temperature detection module, and an oil pressure detection module. The exhaust temperature detection module, axle temperature detection module, oil temperature detection module, and oil pressure detection module are connected to the control box module via signal cables. The oil pressure detection module includes an oil pressure sensor to monitor the lubricating oil pressure in the main oil passage of the air compressor in real time. The oil temperature detection module includes a PT100 temperature sensor to detect the lubricating oil temperature. The axle temperature detection module includes a thermocouple sensor to monitor the axle temperature of the main bearing. The exhaust temperature detection module includes a high-temperature resistant temperature sensor to monitor the exhaust temperature. The control box module is pre-set with two levels of comparison parameters: an alarm threshold and a shutdown threshold. After receiving monitoring data from the oil pressure sensor, PT100 temperature sensor, thermocouple sensor, and high-temperature resistant temperature sensor, it analyzes and compares the lubricating oil pressure, oil temperature, main bearing axle temperature, and exhaust temperature. When the monitored data reaches the alarm threshold, an alarm indicator light signal is output; when the monitored data reaches the shutdown threshold, an air compressor shutdown command is output, realizing graded control for abnormal warning and fault shutdown.

[0008] Furthermore, the oil pressure sensor is installed in the main oil passage of the air compressor via a tee connector, and the connection is sealed with an oil-resistant gasket.

[0009] Furthermore, the PT100 temperature sensor is installed in the oil sump at the bottom of the air compressor's mechanical housing, with a detection accuracy of ±1℃.

[0010] Furthermore, thermocouple sensors are embedded in the front and rear bearing caps of the crankshaft.

[0011] Furthermore, a high-temperature resistant temperature sensor is installed at the compressed air exhaust port of the air compressor, with a range of 0-300℃.

[0012] Furthermore, the control box module uses an STM32F103 chip. The control box module is connected to the air compressor motor power supply circuit through a detection module relay. The detection module relay uses normally closed contacts to control the on / off state of the air compressor motor power supply circuit.

[0013] The beneficial effects of this utility model are: 1. Achieve comprehensive monitoring of air compressors: Real-time monitoring of technical parameters such as lubricating oil pressure, lubricating oil temperature, main bearing shaft temperature, and compressed air exhaust temperature during air compressor startup and operation, covering key operating parameters of air compressors and avoiding the limitations of monitoring with a single oil pressure gauge.

[0014] 2. Implement a graded protection mechanism for air compressors: set alarm and pump stop thresholds in a tiered manner to provide early warning of abnormal conditions, reduce the probability of downtime due to malfunctions, and ensure rapid response in the event of a malfunction.

[0015] 3. Achieve intelligent control: Automatically identify multiple types of faults, reduce the burden of manual inspection, and improve the safety and reliability of locomotive operation. Attached Figure Description

[0016] Figure 1 This is the electrical control schematic diagram of this utility model; Figure 2 This is a schematic diagram showing the connection between the control box module and each detection module in this utility model; Figure 3 This is the circuit diagram of the control box module in this utility model; Figure 4 This is the circuit diagram of the oil pressure monitoring module in this utility model; Figure 5 This is the circuit diagram of the oil temperature detection module in this utility model; Figure 6 This is the circuit diagram of the shaft temperature detection module in this utility model; Figure 7 This is the circuit diagram of the exhaust temperature detection module in this utility model; Figure 8 This is the power supply circuit diagram of this utility model; Figure 9 This is the circuit diagram of the alarm indicator and fault code display module in this utility model; Figure 10This is the circuit diagram of the detection module relay in this utility model. Detailed Implementation

[0017] The preferred embodiments of the present invention will now be described with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0018] A multi-parameter monitoring system for an NPT5 type air compressor in a railway diesel locomotive includes a control box module, an exhaust temperature detection module, an axle temperature detection module, an oil temperature detection module, and an oil pressure detection module. The exhaust temperature detection module, axle temperature detection module, oil temperature detection module, and oil pressure detection module are all connected to the control box module. The oil pressure detection module includes an oil pressure sensor installed in the main oil passage of the air compressor via a three-way connector to monitor the lubricating oil pressure in the main oil passage in real time. The oil temperature detection module includes a PT100 temperature sensor installed in the oil sump at the bottom of the air compressor's mechanical housing, with a detection accuracy of ±1℃, used to detect the lubricating oil temperature. The axle temperature detection module includes a thermocouple sensor embedded in the front and rear bearing caps of the crankshaft to monitor the shaft temperature of the main bearing. The exhaust temperature detection module includes a high-temperature resistant temperature sensor installed at the compressed air exhaust port of the air compressor, with a range of 0-300℃, used to monitor the exhaust temperature. The control box module uses an STM32F103 microcontroller. The chip has two levels of comparison parameters: alarm threshold and shutdown threshold. After receiving monitoring data from the oil pressure sensor, PT100 temperature sensor, thermocouple sensor, and high-temperature resistant temperature sensor, it analyzes and compares the lubricating oil pressure, oil temperature, main bearing shaft temperature, and exhaust temperature. When the monitored data reaches the alarm threshold, it outputs an alarm indicator signal. When the monitored data reaches the shutdown threshold, it outputs an air compressor shutdown command, realizing graded control of abnormal warning and fault shutdown.

[0019] The control box module is connected to the air compressor motor power supply circuit through the detection module relay. The detection module relay uses normally closed contacts to control the on and off of the air compressor motor power supply circuit. Example

[0020] Taking the installation of a multi-parameter monitoring system for the NPT5 type air compressor of the internal combustion engine on the GK1C locomotive as an example: like Figure 1 and Figure 2As shown, the control box module is installed in the air compressor's electrical control cabinet, connecting to the exhaust temperature detection module, shaft temperature detection module, oil temperature detection module, and oil pressure monitoring module to collect data on lubricating oil pressure, oil temperature, main bearing shaft temperature, and exhaust temperature. The control box module is connected to the air compressor motor control circuit via a monitoring module relay, which uses normally closed contacts to control the power supply to the air compressor motor control circuit. The control box module also connects to an LED alarm circuit and outputs alarm indication signals. Two threshold levels (alarm / stop) can be set via the control box module. When the monitored data exceeds the alarm threshold, an alarm light and fault code (1-low oil pressure, 2-high oil temperature, 3-high shaft temperature, 4-high exhaust temperature) are triggered.

[0021] The specific circuit connections for the control box module, oil pressure monitoring module, oil temperature detection module, shaft temperature detection module, exhaust temperature detection module, and power supply are as follows: Figures 3 to 8 As shown The oil pressure sensor of the oil pressure monitoring module is installed at the annular connection of the oil pressure gauge. A tee is added to connect the oil pressure sensor and the oil pressure gauge in parallel. After the oil pressure monitoring module is installed, the air compressor operates normally and maintains its original working state when the air compressor lubrication system is normal. Assuming a lubrication system failure: the annular pipe interface is blocked, the oil pressure sensor cannot detect lubricating oil pressure. When the air compressor is started, the oil pressure gauge displays 0 kPa, and the air compressor automatically stops after 5 seconds of operation, achieving the design objective.

[0022] The PT100 temperature sensor of the oil temperature detection module is located at the bolt hole at the bottom of the mechanical housing wall, extends into the bottom of the oil sump and is sealed; the thermocouple sensor of the shaft temperature detection module is installed at the outer bearing cap at both ends of the crankshaft bearing; the high-temperature resistant temperature sensor of the exhaust temperature detection module is installed on the wall of the air compressor exhaust pipe by drilling.

[0023] The comparison parameters preset in the control box module include: Main oil passage lubrication oil pressure: Set the standard value of main oil passage lubrication oil pressure to 440 kPa, alarm when main oil passage lubrication oil pressure ≤350 kPa, and pump stop threshold when ≤200 kPa. Lubricating oil temperature: The standard value for the main oil passage lubricating oil temperature is set to ≤80℃. An alarm is triggered if the oil temperature reaches ≥85℃, and a pump stop threshold is set if the temperature reaches ≥90℃. Main bearing temperature: Set the standard value for main bearing temperature to ≤80℃. Alarm for shaft temperature ≥85℃, pump stop threshold for ≥95℃; Exhaust temperature: Set exhaust temperature ≤185℃. Alarm at exhaust temperature ≥190℃, pump stop threshold at exhaust temperature ≥210℃.

[0024] The control box module outputs LED alarm light signals and air compressor shutdown control commands: Air compressor malfunction LED alarm: An alarm indicator light is installed on the operator's cab control panel. When the values ​​collected by the control box from each module exceed the preset alarm values, the control box outputs an alarm signal, the yellow alarm indicator light illuminates, and the corresponding code is displayed, such as... Figure 9 As shown, the codes represent the fault names. 1-Low lubricating oil pressure, 2-High lubricating oil temperature, 3-High main bearing temperature, 4-High exhaust temperature.

[0025] Air compressor fault shutdown control: When the values ​​collected by the control box from each module reach the preset shutdown value, the control box outputs a control signal to control the relay of the detection module to operate. The relay circuit of the detection module is as follows: Figure 10 As shown, its normally closed contact disconnects the negative terminal of the air compressor control circuit, de-energizing the air compressor control contactor, and its main contact disconnects the power supply circuit to the air compressor motor. Simultaneously, an alarm signal is output, the red alarm indicator light illuminates, and the corresponding code is displayed, representing the fault name: 1-Low lubricating oil pressure, 2-High lubricating oil temperature, 3-High main bearing temperature, 4-High exhaust temperature.

[0026] The control principle is as follows: After the locomotive starts generating electricity, pressing the air compressor control switch will cause the main air reservoir pressure to close if it is below 750 kPa, thus activating the control circuit. The power supply connects the 110V positive terminal to the air compressor control switch, then to the main air pressure relay, then to the air compressor motor contactor coil, then to the normally closed contact of the detection module relay, and finally to the 110V negative terminal. The air compressor motor contactor is energized, its main contacts close, and the motor drives the air compressor to start. The lubricating oil pump operates synchronously. When the control box detects that the values ​​collected by the monitoring modules have not reached the alarm and shutdown thresholds, the contactor coil remains energized through the normally closed contact of the monitoring module relay, allowing the air compressor to continue running.

[0027] Air compressor fault alarm principle: If the oil pressure does not reach 440kPa within 5 seconds of starting the air compressor, or if the oil pressure drops below 350kPa during operation, or if the oil temperature is ≥85℃, shaft temperature ≥85℃, or exhaust temperature ≥190℃ during operation, the corresponding monitoring module will activate, the yellow light on the operator's cab control panel will illuminate, and a digital code alarm will be displayed. When both faults occur simultaneously, the corresponding fault codes will flash alternately. In this case, the corresponding fault of the air compressor should be checked and addressed.

[0028] The principle of air compressor fault control shutdown is as follows: When the lubricating oil pressure is ≤200kPa, the lubricating oil temperature is ≥90℃, the main bearing shaft temperature is ≥95℃, or the exhaust temperature is ≥210℃, the control box outputs the control monitoring module relay circuit. Its normally closed contact disconnects the air compressor contactor control circuit, the air compressor stops, the red light illuminates, and the fault code is displayed. This achieves the protective purpose of promptly cutting off the air compressor motor control circuit and stopping the air compressor in case of faults in the air compressor's lubrication system or mechanical parts, thereby allowing for the identification and timely handling of the corresponding fault causes.

[0029] After the GK1C locomotive was equipped with this utility model system, during the trial operation, it was detected that the oil temperature rose to 85°C due to lubricating oil contamination, triggering a yellow alarm and prompting the lubricating oil to be replaced to prevent the oil temperature from rising further. On another occasion, the shaft temperature reached 96°C due to main bearing wear, and the system automatically stopped the pump. After inspection, it was confirmed that the bearing clearance exceeded the standard, and it was restored to normal after replacement.

[0030] This system can promptly and accurately identify and warn of air compressor failures caused by lubrication system malfunctions and mechanical component failures. In the event of a serious malfunction, it can automatically control the air compressor to shut down, thereby reducing losses caused by air compressor system failures, lowering maintenance costs, improving locomotive utilization, and ensuring the safe and stable operation of locomotives.

[0031] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A multi-parameter monitoring system for an NPT5 type air compressor in a railway diesel locomotive, characterized in that: The system includes a control box module, an exhaust temperature detection module, a shaft temperature detection module, an oil temperature detection module, and an oil pressure detection module. The exhaust temperature detection module, shaft temperature detection module, oil temperature detection module, and oil pressure detection module are connected to the control box module via signal cables. The oil pressure detection module includes an oil pressure sensor to monitor the lubricating oil pressure in the main oil passage of the air compressor in real time. The oil temperature detection module includes a PT100 temperature sensor to detect the lubricating oil temperature. The shaft temperature detection module includes a thermocouple sensor to monitor the shaft temperature of the main bearing. The exhaust temperature detection module includes a high-temperature resistant temperature sensor to monitor the exhaust temperature. The control box module uses an STM32F103 chip and has pre-set alarm and shutdown thresholds as comparison parameters. After receiving monitoring data from the oil pressure sensor, PT100 temperature sensor, thermocouple sensor, and high-temperature resistant temperature sensor, it analyzes and compares the lubricating oil pressure, oil temperature, main bearing shaft temperature, and exhaust temperature. When the monitored data reaches the alarm threshold, it outputs an alarm indicator signal; when the monitored data reaches the shutdown threshold, it outputs an air compressor shutdown command, realizing graded control for abnormal warning and fault shutdown.

2. The multi-parameter monitoring system for NPT5 type air compressor of railway diesel locomotive according to claim 1, characterized in that: The oil pressure sensor is installed in the main oil passage of the air compressor via a three-way connector, and the connection is sealed with an oil-resistant gasket.

3. The multi-parameter monitoring system for NPT5 type air compressor of railway diesel locomotive according to claim 1, characterized in that: The PT100 temperature sensor is installed in the oil sump at the bottom of the air compressor's mechanical housing, with a detection accuracy of ±1℃.

4. The multi-parameter monitoring system for NPT5 type air compressor of railway diesel locomotive according to claim 1, characterized in that: The thermocouple sensor is embedded in the front and rear bearing caps of the crankshaft.

5. A multi-parameter monitoring system for an NPT5 type air compressor in a railway diesel locomotive according to claim 1, characterized in that: The high-temperature resistant temperature sensor is installed at the compressed air exhaust port of the air compressor, with a range of 0-300℃.

6. The multi-parameter monitoring system for NPT5 type air compressor of railway diesel locomotive according to claim 1, characterized in that: The control box module uses an STM32 chip, model STM32F103C8T6. The control box module is connected to the air compressor motor control circuit through a detection module relay. The detection module relay uses normally closed contacts to control the power supply to and from the air compressor motor control circuit.

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